RIO DE JANEIRO, Dec 17 (Reuters) - Brazil’s National Council for Energy Policy (CNPE) in a meeting on Monday approved the sixth-round auction for the country’s pre-salt offshore oil area to be held on Nov. 1, 2019, a person with knowledge of the matter told Reuters.

Global oil companies have spent billions of dollars to lock down coveted blocks in the area, where billions of barrels of oil are trapped under a layer of salt offshore.

Brazil’s election of far-right President-elect Jair Bolsonaro has called into question the future of Brazil’s pre-salt oil auctions, with sources telling Reuters last month that his government could seek to switch to concession contracts for the areas instead of the current production-sharing agreements. The future chief of Petroleo Brasileiro SA under Bolsonaro has said a decision has not been made on the matter.

CNPE additionally approved a 16th-round auction of oil areas under the concession regime, to be held on Oct. 2, 2019, the source said, on condition of anonymity.

The council did not discuss a prospective auction of surplus oil volumes from the so-called transfer-of-rights oil area in the Santos Basin at the meeting, the source said. The area has been the subject of a dispute between the government and state-run Petrobras since the oil company signed a contract on it in 2010. (Reporting by Marta Nogueira Writing by Jake Spring Editing by Chizu Nomiyama and Jonathan Oatis)